| Objective: To study recent effects of mandibular overdenture supported by two implants with ball attachments for the restoration of edentulous patients,so as to provide a reference for restoration of edentulous mandible in clinical work.Methods: 1.The 14 patients who had used mandibular overdentures with a period of 1 to 2 year were objects of study.They were completely edentulous patients who had applied conventional dentures to restore dentitions.Their conventional dentures of mandible had been replaced by overdentures because of poor retention.2,Before and after implantation,a questionnaire survey had been conducted to investigate the quality of oral related life.Before and after implant loading,the peri-implant parameters had been examed,such as the plaque index,gingival index,bleeding index,probing depth,marginal bone loss and survival rate of implant.3.Masticatory efficiency was measured by bi-color gum mixing test.Viewgum software was used to analyze the mixture after chewing.The masticatory efficiency was defined by SDHue.4.The pre-experiment had been designed to analysis masticatory efficiency of patients and participants with normal dentition.The hypothesis of difference test and non inferiority test had been put forward.Their differences were quantitatively evaluated by statistical methods.Results: 1.Questionnaire survey results showed that the quality of oral-related life after application of 2BOD to mandible was better than that of CCD..Improvement was mainly reflected in five aspects: functional limitations,physiological pain,psychological discomfort,physical disorders,and mental disorders.The differences were statistically significant.2.There was no significant difference between before and after 1~2 years of loading in peri-implant parameters.The survival rate of implant was 100%.The marginal bone loss of all implants were less than 1.5mm within an average of0.64±0.27 mm.3.The masticatory efficiency of application of 2BOD was higher than that of CCD,and the difference was statistically significant.The difference was also statistically significant below that of normal dentition subjects,but the difference was less than 0.25 on SDHue.Conclusion:For the restoration of edentulous mandible,overdenture supported by two implants with ball attachments is a solution that can improve the quality of life of the patient's mouth,improve the chewing function,and have a reliable recent effect when compared with conventional denture.However,there is still room for improvement compared to the normal masticatory efficiency. |
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